Well tool construction



March 22, 1938. A. c. CATLAND WELL TOOL CONSTRUCTION Filed April 15,1936 Patented Mar. 22, 1938 ,lllJSl WELL EOUL CGNS'ERIUCTHON Alfred C.Catland, Alhambra, Calif assignor to Globe Gil Tools Company, LosNietos, Calif... a corporation of California Application April 13, 1936,Serial No. 74,165

4 Claims.

Thisinvention relates to well drilling tools and relates moreparticularly to well drilling tools embodying roller cutters. A generalobject of this invention is to provide an improved, efficient and verysimple bearing means for the roller cutters of a well tool.

Another object of this invention is to provide a well tool constructionembodying an easily manufactured roller cutter mounting that isefiicient and long wearing.

Another object of this invention is to provide bearing means forrotatably supporting the roller cutter of a well bit that efiects theproper transmission and the even distribution of the load or drillingforces on the cutter.

I Another object of this invention is to provide a well toolconstruction embodying roller cutters and bearing means for the cuttershaving thrust receiving faces normal or perpendicular to the directionof the forces transmitted through the cutters whereby there is a minimumend thrust on the cutters. Another object of the invention is to providea well tool assembly of the character mentioned embodying plain bearingsarranged on threaded pins and located to dependably receiveand transomitthe forces resulting from the engagement of the cutters with the earthformation.

The various objects and features-of my invention will be fullyunderstood from the following detailed description of a. typicalpreferred form and application of the invention, throughout whichdescription reference is made to the accompanying drawing, in which:

Fig. l is a side elevation of a well tool embodying the presentinvention, showing the principal portions of the tool in longitudinalcross section. Fig. 2 is an enlarged fragmentary longitudinal detailedsectional view illustrating the mounting of one of the inner cutters.Fig. 3 is a view similar to Fig. 2 illustrating the mounting of one ofthe outer cutters. Fig. 4 is a perspective view of the thrust washerembodied in the mounting of one of the inner cutters. Fig. 5 isaperspective view of the bearing of one of the inner cutter mountings.Fig. 6 is a perspective view of the bearing embodied in the mounting ofan outer cutter and Fig. 7 is the thrust washer of an outer cuttermounting means.

The assembly or construction provided by the present invention isadapted to be embodied in well tools varying considerably in character.In the following detailed description the invention will be disclosed asembodied in the core drill illustrated in the drawing, it beingunderstood that the invention is not to be construed as limited orrestricted to the specific application disclosed.

The core drill illustrated in the drawing comprises an outer barrel Illprovided at its lower end with a sub i l. A tubular member I2 is fixedwithin the sub ii in spaced relation to its inner wall leaving anannular fluid passage it. A core catcher it is arranged in the tubularmember if. The core catcher it illustrated is similar, generally,'to thecore catcher fully described and claimed in'the co-pending applicationof John H. Howard, entitled Core recovering means, Serial No. 34,649,filed August 5, 1935, matured into Patent No. 2,063,437, grantedDecember 8, 1936. An inner barrel it extends longitudinally through theouter barrel IE to receive the core. The inner barrel I5 is spaced fromthe interior of the outer barrel in leaving an annular fluid passageiii. The passages l6 and is are in communication and conduct or pass thecirculation fluid downwardly to the bit head. A collar H is provided onthe lower end of the inner barrel it. The collar H is rotatable betweenthe upper end of the member l2 and a shoulder it to rotatably supportthe inner barrel l6.

The bit head or cutting head embodying the present invention comprises,generally, a head body 20 secured to the sub ii and having series ofrecesses A and B in its lower end, outer cutters X, inner cutters Y,means 2i rotatably supporting the outer cutters X in the recesses A andmeans 22 rotatably supporting the inner cutters Y in the recesses B.

The shoe or body 20 of the cutting head is tubular having a centrallongitudinal opening 23. The body 20 is secured to the sub it so thatits opening 23 is aligned with the inner barrel l5. In the particularcase illustrated in the drawing the body 20 is threaded on a pin 24 onthe lower end of the sub ii. The lower end portion of the body 20 isthickened or provided with wings 25. The recesses A and B for carryingthe cutters X and Y are provided in the lower end of the body 20. Therecesses A are inclined having their inner and outer walls inclineddownwardly and outwardly relative to the longitudinal axis of the tool.A slightly raised surface 26 is provided on the outer wall of eachrecess A. The inner walls 21 of the recesses A are fiat and parallelwith the surfaces 26. Flat faces 28 are provided on the lower end of thebody 20 at the lower ends of the surfaces 26 and the walls 21. Therecesses B for carrying the inner cutters Y are inclined downwardly andinwardly having inclined walls. A raised surface 29 is provided on theinner wall of each recess B and is inclined downwardly and inwardly withrespect to the longitudinal axis of the tool. The outer walls 30 of therecesses B are flat and parallel with the raised surfaces 29. Flatdownwardly facing surfaces 3| are provided on the body 20 at the lowerends of the raised surfaces 29. Downwardly facing shoulders 32 occur onthe wings 25 at the lower ends of the walls 30. The number and thespacing of the recesses A the recesses A and B. Ports II are provided inthe sub ii to conduct the circulation fluid downwardly from the passage|3 to ports 10 in the body which discharge into the recesses A and B.

The outer cutters X are provided to act on the formation at the bottomof the well bore to cut the well bore to gauge. The cutters X arerotatably supported by the means 2| to project downwardly and outwardlyfrom the lower ends of the recesses A. In accordance with the inventionthe outer cutters X are frusto-conical having their peripheries inclinedor pitched. Axially extending cutting parts or teeth 33 are provided onthe peripheries of the cutters X. Central longitudinal openings 34extend through the outer cutters X. A central socket 35 enters eachcutter X from its outer end. In accordance with the invention thesockets 35 are conical or frustoconical as illustrated in the drawing.The pitch of the walls of the sockets 35 is in the same direction as theperipheries of the cutters X and is substantially the same as the pitchof the teeth 33 and the peripheries of the cutters. The bottom or innerwalls of the sockets 35 are fiat and normal to the longitudinal axes ofthe cutters. The opposite ends of the cutters X are fiat and normal.

The inner cutters Y are rotatably supported in the recesses B to cut andtrim the core and to act on the formation at the bottom of the Wellbore. The cutters Y are in the nature of cylindrical roller cutters. Theinner cutters Y have fiat normal ends and axial peripheral cutting partsor teeth 36. Central longitudinal openings 31 are provided in thecutters Y. Central sockets 38 of substantial depth are provided in theinner ends of the cutters Y. The sockets 38 are cylindrical havingcylindrically curved walls concentric with the longitudinal .axes of thecutters. The bottom walls or inner end walls of the sockets 38 are flatand normal to the axes of the cutters. The extreme outer end portions ofthe sockets 38 are flared or enlarged at 39.

The means 2| rotatably support the cutters X in the recesses A forrotation about downwardly and inwardly inclined axes. Each cuttermounting means 2| includes a screw or pin 40 extending through a recessA. The cutter supporting pins 4|] are arranged outwardly throughopenings 4| in the inner wall portions of the body 20 and their outerparts are threaded in openings 42 in the wings 25. The openings 4| and42 are inclined downwardly and inwardly and carry the pins 40 so thattheir longitudinal axes are substantially normal to the surfaces 26 andthe walls 21. Suitable heads 43 are provided on the inner ends of thepins 40. The heads 43 and the outer ends of the pins 40 may be groundaway or bevelled to be flush with the adjacent body surfaces. The pins40 pass freely through the openings 34 in the cutters X. Each pin 40 isprovided between its ends with an outwardly facing annular shoulder 44.The shoulders 44 and the inner end walls of the sockets 35 are in oradjacent a common plane.

The means 2| rotatably supporting the cutters X include bearings 45 onthe pins 40 cooperating with the sockets 35. The bearings 45 arefrustoconical having fiat normal ends and pitched or inclinedperipheries 45. The inner ends and the peripheries of the bearings 45are hard faced being provided with layers 41 of hard wear resistingmaterial. The walls of the sockets 35 and the peripheries 45 of thebearings 45 have their lower parts parallel with the face of the earthformation engaged by the cutting teeth 33 and are, therefore,substantially perpendicular to the direction of the forces on thecutters X resulting from the action of the cutters on the formation.This disposition of the bearings 45 and the sockets 35 reduces the endthrusts on the cutters X to a minimum. The inner ends of the bearings 45are engaged by the shoulders 44 on the pins 40 whereby the bearings areheld or clamped between the shoulders 44 and the raised surfaces 25. Theouter ends of the bearings 45 have extensive engagement with the raisedsurfaces 26. The invention provides means for holding the bearings 45against rotation. Integral lugs 48 are provided on the bearings 45 tocooperate with the faces 28 on the wings 25. The cutter mounting means2| may include replaceable thrust washers 49 arranged on the pins 40between the inner ends of the cutters X and the walls 21 of the recessesA. Integral lugs 50 on the thrust washers 49 cooperate with faces 28 onthe body 20 to hold the washers against turning.

The means 22 support the cutters Y in the recesses B to rotate aboutdownwardly and outwardly inclined axes. The means 22 includes pins 5iextending through the recesses B. The pins 5| are passed inwardlythrough openings 52 in the wings 25 and have their inner end portionsthreaded in openings 53 in the inner part of the body wall. The heads 54of the pins 5| are suitably countersunk in the outer sides of the wings25. The pins 5| are shouldered between their ends each having aninwardly facing annular shoulder 53.

The cutter mounting means 22 includes bearings 55 on the pins 5|rotatably carrying the cutters Y. The bearings 55 are cylindrical andhave fiat normal ends. The inner ends of the bearings 55 cooperate withthe raised surfaces 29. The outer ends of the bearings 55 are engaged bythe shoulders 53. The bearings 55 are held or clamped between theshoulders 53 and the surfaces 29. The peripheries and the outer ends ofthe bearings 55 are faced with layers 56 of hard wear resistingmaterial. The peripheries of the bearings 55 cooperate with the walls ofthe sockets 35 to rotatably support the cutters Y so that the walls oftheir openings 31 have suitable clearance with the pins 5|. Theperipheries of the bearings 55 and the walls of the sockets 38 areconcentric with the series of teeth 35 whereby they are perpendicular tothe direction of the forces on the cutters Y resulting from itsengagement with the formation. This relationship of parts reduces theend thrusts on the cutters Y to a minimum. The cutters Y are rotatablysupported by the bearings 55 so that they are free of contact with thebody. The cut away or flared parts 39 of the cutter sockets 38 havesuitable clearance with the raised parts of the recess walls 29. Theouter ends of the bearings 55 cooperate with the bottom walls of thesockets 38 to receive the principal end thrusts from the cutters Y.Integral lugs 51 are provided on the bearings 55 and cooperate with thesurfaces 3| to hold the bearings against rotation. The cutter mountingmeans 22 includes replaceable thrust washers 60 arranged on the pins 5|between the outer ends of the cutters Y and the outer walls 30 of therecesses B. Means are provided for holding the washers 80 againstrotation. Integral lugs 6| are provided on the washers Cl and cooperatewith the shoulders 32 to hold the, washers against turning. The cuttersY rotatably mounted by the means 22 project from the lower ends of therecesses B and their cutting parts or teeth 36 are inclined downwardlyand outwardly as they come into engagement with the earth formation. The

active parts of the cutters Y project inwardly at the lower end of theopening 23 to trim the core for reception in the opening a.

In operation the outer barrel I is connected with the lower end of adrilling string and the tool is rotated and fed downwardly in the well.The cutters x and Y make an annular cut in the earth formation and leavea core which is received in the opening 23 and the inner barrel IS. Theports III in the body 20 carry the circulation fluid downwardly from theports H. to the recesses A and B to flush the cutters. The cutters x aredependably supported on the bearings 45 for free rotation aboutdownwardly and inwardly inclined axes. The frusto-conlcal cutters X aremounted so that their teeth 36 are substantially horizontal as they comeinto engagement with the earth formation. The lower-most parts of thebearings 45 and the lower-most wall surfaces of the sockets 35 are alsosubstantially horizontal. Thus the forces resulting from the engagementof the cutters x with the formation are substantially vertical andnormal to the cooperating peripheries of the bearings 45 and the wallsof the sockets IS. The thrusts or forces are transmitted through thebearings ll evenly and with minimum end thrust on the cutters. In actualpractice it has been found that the principal or heavier forces on theouter cutters are closer to the outer ends of the cutters and thebearings 48 are positioned where they fully receive and transmit theseforces. The bearings I! being hard faced are long wearing and as theoperating thrusts and forces are evenly distributed the assembly isparticularly long wearing.

The cutting parts 38 of the cutters Y are inclined downwardly andoutwardly as they come into engagement with the earth formation and thethrusts or forces resulting from this action act along lines inclineddownwardly and inwardly. The walls of the sockets 38 and the periphcriesof the bearings 55 are concentric with the peripheral cutting teeth 36so that the force transmitted through the cutters Y act along linessubstantially normal to the axes of curvature of the peripheries of thebearings III and the walls of the sockets 38. Because of thisrelationship between the parts there is a minimum end thrust on thecutters Y and the operating forces and thrusts are evenly distributed.The end thrusts are directly taken by the bearings II which in tin-ndirectly bear on the body surfaces 29. The cutter mounting means II and22 of the present invention are very simple and inexpensive. and areeflective and dependable. The cutter moimting means are long wearing andthe cutters and the other parts may be easily and quickly replaced.

Having described only a typical preferred form and application of myinvention I do not wish to be limited or restricted to the specificdetails 70 hercinsetfortnbutwishtoreservetomyseli'sny thrusts to thesaid ends variations or modifications that may appear to those skilledin the art or fall within the scope of the following claims:

Having described my invention, I claim:

1. In a well bit, a body, a pin carried by the body and inclineddownwardly and inwardly relative to the vertical axis of the body, aconical bearing on the pin having its base at the higher portion of thepin and having a flat normal inner end, and a tapered roller cutterhaving a tapered socket entering its outer end and having a lengthgreater than one-half the length of the cutter and having a flat innerend wall, the socket rotatably receiving the bearing to receive theprincipal cutter thrusts, the end wall of the socket having end thrustengagement with the inner end of the bearing.

2. In a well bit, a body, a pin carried by the body and inclineddownwardly and inwardly relative to the vertical axis of the body, aconical bearing on the pin having its base at the higher portion of thepin, and a conical roller cutter having a conical socket in its baseportion rotatably receiving the bearing whereby the cutter is rotatableon the bearing, the surface of the conical bearing and the wall of theconical socket being substantially parallel with the active outersurface of the conical the socket having a length at least one half asgreat as the length of the cutter whereby the bearing receives theprincipal thrusts.

3. A core bit comprising, a body having spaced recesses at its lowerend, downwardly and inwardly inclined pins extending through certain ofthe recesses, downwardly and outwardly inclined pins extending throughthe other recesses, tapered on the first mentioned pins having their atthe higher portions of the pins, and having fiat normal inner ends,tapered outer roller cutters having tapered sockets in their outer endsrotatably receiving the bearings and having flat inner end wallstransmitting end of the bearings, the tapered sockets and bearingshaving a length greaterthan one half the length of the cutters wherebythe conical surfaces of the bearings receive the principal end thrusts,cylindrical bearings on the downwardly and outwardly inclined .pins, andcylindrical inner roller cutters rotatable on the last named bearings.

4. A core bit comprising, a body having spaced recesses at its lowerend, downwardly and inwardly inclined pins extending through certain ofthe recesses, downwardly and outwardly inclined pins extending throughthe other recesses, tapered bearings on the first mentioned pins havingtheir bases at the higher portions of the pins, fmsto-conical outercutters rotatably supported on the tapered bearings, the active outersurfaces of the cutters being substantially parallel with the surfacesof the conical bearings, cylindriq cal bearings on the inner portions ofthe downwardly and outwardly inclined pins, and cylindrical inner rollercutters having sockets in their inner ends rotatably receiving thecylindrical bearings, the sockets and bearings having lengths greaterthan one half the lengths of their re spective cutters whereby thebearings receive the cutter, the bearing and-

